Study On Agricultural Substrate Development And Application Of Hickory Hull

Hickory hull waste is the important ecological and environmental protection problem inthe development industry of hickory in the north-west of Zhejiang province，specially in Lin-anCity. Coconut shell waste as agricultural substrate for large-scale processing of successful experienceon abroad is an object lesson for studying on starting fermentation strain on the hickory hull rettingscreening, identification and culture and in different application conditions in Hickory Hullretting reactor, and hickory hull combination of retting process observation and post-treatmenttechnique, comparing growth effect of greening seedlings under different processing substrates,so as to explore the hickory hull as a feasible approach for agricultural substrate material scaleand resource recycling. The main results are as follows:1) Fermentation strains for hickory hull are a group composite fermentation flora, incluingLactic acid bacteria, Actinomycete, Bacillus, Photosynthetic bacteria, Saccharomyces, etc. Inwhich, starting fermentation strains for hickory hull retting is Bacillus sp., called F46, which isrod-shaped, gram-positive, and high similarity with Bacillus thuringiensis model ATCC10792;strain F46can store up to-4oC refrigerator. Strain F46grows stably after the16h; the optimumculture temperature is37oC, when temperature is less than4℃and higher than55℃, it stopsgrowth; the best pH value for culture is7.2) In hickory hull retting processing, Fermentation strains (including stain F46) will beadded in hickory hull according to0.2%of the concentration ratio and. To add the amount ofwood cuttings and sawdust or cow-dung can increase the aggregate porosity, to act on thereactor temperature increases rapidly, and to increased N bean, although it can improve thereactor temperature, but will also to maintain a longer time to high temperature, resulting in theneed for very long retting time, but will make the decline in its retting quality.3) In A, B, C and D stacking for hickory hull, the best initial water content for hickory hullretting is about65%; the best retting reactor pH value is8, the general10d can be achievedafter retting. 4) After hickory hull retting reactor, the EC value was significantly higher than that of itsinitial value, and the4ratio of hickory hull were higher than the threshold1.25ms·cm-1forseedling growth, and the treatment A is the maximum,5.5ms·cm-1. It still need throughtwin-screw continuous extrusion of alkaloids and removal and substrate modification and canmake the EC to0.2-0.5ms·cm-1, and cation exchange capacity (CEC) increased frompretreatment7.2mol·kg-1to treatment30.9mol·kg-1.5)4ratio of hickory hull of total C material after retting showed a downward trend inthem, and the total N content changes little; the amount of total P, total K content changed little.4ratio of hickory hull of initial C/N material are respectively7.5,26.4,22.1and27.3, therefore,B, D2ratio of hickory hull in the carbon and nitrogen suitable compost ratio (C/N)25~30range, the ratio of C stacking is close to the carbon and nitrogen suitable compost ratio range.6) A, B, C, D and other4kinds of stacking in the color after retting are brown, otherphysical traits of hickory hull, the treatment C was the best, the density is0.317g·cm-3, totalporosity is90%, the size of the pore ratio is0.66, and saturated water content is832%.7) Growth comparison of Photinia fraseri in A, B, C, D of4kinds of retting material isdemonstrated by B, C two kinds of treatment is better hickory hull retting, namely (B)60%hickory hull+20%sawdust+10%cow-dung+10%carbonized rice husk or (C)60%hickoryhull+10%sawdust+20%cow dung+10%carbonized rice husk, and the retting time is44days or56days.8) After retting, hickory hull substrate in the physical and chemical properties of theoverall slightly compared to bran material quality of coconut plant which is the internationallyrecognized, but the permeability, water holding capacity and CEC is much better than coconutcoir. Therefore, hickory hull treated as substitute materials for imported coconut coir.9) Photinia fraseri grows best in hickory hull substrate, the average plant height reached16.1cm, and was significantly higher than other treatments (p<0.05), while the other substratebetween difference, amplitude in11.6cm-12.5cm.10) Hickory hull, coconut shell, peat and bark substrate are light substrate. In which, thehickory hull of density is high than peat and bark, and adhesive ability, more easily fixedseedling root; its maximum water holding capacity is the highest, with good water retention and stability; its water-gas ratio of hickory hull substrate is1.7, which is very conducive to thegrowth of seedlings.11) The eluent conductivity of4kinds of substrate, the hickory hull, coconut husk,sawdust and bark substrate is0.4~0.7ms·cm-1., this result indicated that the four kinds ofsubstrate have good fertilizer performance. The pH values in4kinds of substrate were in growthpH range of seedling. Leaching solution P content of hickory hull in four kinds of substrate isthe highest as8.93mg·kg-1.12) After plant8weeks for Photinia fraseri, the seedling height only had significant linearcorrelation with the substrate maximum water holding capacity, this result indicating that thewater holding capacity of substrate is to determine the factors which affect the growth ofseedlings.